JP3912201B2 - Cell module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cell module in which a plurality of tab-type cells such as a sheet-like thin battery are stacked and arranged.
[0002]
[Problems to be solved by the invention]
A thin battery as disclosed in Japanese Patent Application Laid-Open No. 9-259859 is known as a tab-type cell in which a sheet-like positive electrode terminal and a negative electrode terminal are drawn from both ends of a cell body. In order to obtain a high-voltage, high-capacity battery using these cells, it is necessary to form a battery pack by connecting a plurality of cells in series or in parallel. When connecting the tab terminals of the cells that are vertically stacked, it is necessary to connect the tab terminals by bending them. For this reason, stress is generated in the tab terminal portion, and the durability and reliability of the tab terminal may be reduced.
[0003]
An object of the present invention is to provide a cell module that is excellent in durability and reliability without causing unnecessary stress in a tab in a cell module in which a plurality of tab-type cells are stacked and arranged. .
[0004]
[Means for Solving the Problems]
In the cell module according to the present invention, both tab-type cells having a sheet-like positive electrode terminal and a negative electrode terminal are arranged in parallel, and each terminal on the same electrode side is connected to a bus bar arranged in the terminal extending direction. One cell unit is configured. A plurality of cell units are stacked and disposed so that bus bars having different polarities face each other, thereby forming a cell module. The cell module passes through a through-hole formed in the bus bar of each cell unit and penetrating in the stacking direction of the cell unit and through holes of a plurality of bus bars arranged in the stacking direction, and the bus bar is orthogonal to the stacking direction. A positioning member that positions at a predetermined position with respect to the direction, and the positioning member is different from the conductive columnar member that electrically connects bus bars set at the same potential adjacent in the stacking direction and adjacent in the stacking direction. Insulating columnar members that electrically insulate bus bars set to potentials are alternately connected in the stacking direction, and a plurality of cell units are connected in series by conductive columnar members. And
[0005]
【The invention's effect】
According to the present invention, a pair of substantially plate-shaped bus bars is provided for each cell unit composed of a plurality of tab-type cells arranged in parallel, the positive terminals of each cell are on one bus bar, and the negative terminals are Each is connected to the other bus bar. And the bus bars set to the same potential of the adjacent cell units are electrically connected by the positioning member. Therefore, the bus bar can be arranged in the extending direction of each terminal, and can be connected to the bus bar without bending the sheet-like terminal. As a result, it is possible to prevent the terminal from being stressed and to improve the durability and reliability of the terminal portion.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment of a cell module according to the present invention. 1 is a front view of the cell module M, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 3 is a view taken in the direction of arrow B in FIG. The cell module M shown in FIGS. 1 to 3 is composed of 12 cells 1. The cell 1 is a both-tab type cell, and includes a cell body 1a wrapped in a bag-like outer package such as a laminate film, and a sheet-like positive electrode tab 1b and a negative electrode tab 1c extending from the outer periphery of the cell body 1a. I have.
[0007]
FIG. 6 is a view for explaining the internal structure of the cell 1, and is a cross-sectional view on the positive electrode tab 1b side. The cell 1 is a sheet-like lithium ion secondary battery. As shown in FIG. 6, an internal electrode pair 101 and an electrolytic solution 102 are housed in a sealed state inside a flexible bag-like outer package 100. The internal electrode pair 101 includes a sheet-like positive electrode 101a and a negative electrode 101b.
[0008]
The positive electrode 101a is obtained by laminating a positive electrode active material on both surfaces of an aluminum foil positive electrode current collector 104. On the other hand, the negative electrode 101b is obtained by laminating a negative electrode active material on both surfaces of a negative electrode current collector 105 made of copper foil. The positive electrode 101a and the negative electrode 101b are alternately stacked via the separator 101c. Aluminum, an aluminum alloy, or the like is used for the positive electrode tab 1b, and copper, a copper alloy, or the like is used for the negative electrode tab 1c.
[0009]
Each of the positive electrodes 101a is connected to the positive electrode tab 1b. The positive electrode tab 1 b passes through the heat seal portion 103 of the bag-like outer package 100 in an airtight manner and is fixed to the heat seal portion 103. Although not shown, the structure of the negative electrode tab 1c is the same as that of the positive electrode tab 1b, and the negative electrode 101b is connected to the negative electrode tab 1c.
[0010]
The bag-like outer package 100 is formed of a laminate film having a three-layer structure of an inner surface layer 100a, an intermediate layer 100b, and an outer surface layer 100c. For the inner surface layer 100a, a thermoplastic resin excellent in electrolytic solution resistance and heat sealability such as polyethylene, polypropylene, and polyamide is used. For the intermediate layer 100b, a metal foil having excellent flexibility and strength, such as an aluminum foil or a stainless steel foil, is used. For the outer surface layer 100c, an insulating resin excellent in electrical insulation such as a polyamide-based resin or a polyester-based resin is used.
[0011]
The cell module M of the present embodiment includes twelve such cells 1 and the cells 1 are arranged in two rows and six stages as shown in FIG. The two cells 1 in each stage are connected in parallel, and the two cells 1 connected in parallel are connected in series in the vertical direction.
[0012]
As shown in FIG. 2, in the two cells 1 of each stage, the positive electrode tabs 1b are connected to the same bus bar 2A, and the negative electrode tabs are connected to the same bus bar 2B. The bus bars 2A and 2B are provided for each cell in each stage, and the positive electrode tab 1b and the negative electrode tab 1c extending from each cell body 1a are connected to the bus bars 2A and 2B in an extended state without being bent. Yes. For connecting the tabs 1b, 1c and the bus bars 2A, 2B, welding or the like is used. In the present embodiment, a portion constituted by the bus bars 2A and 2B and the two cells 1 connected to them is referred to as a cell unit. That is, as shown in FIG. 1, the cell module M is composed of six cell units U1 to U6, and the plurality of cell units U1 to U6 are connected in series.
[0013]
The cell units are integrated by rods 3A, 3B, and 3C, and the rods 3A, 3B, and 3C at the upper and lower ends are fixed to the insulating panels 4A and 4B, respectively. FIG. 4 is an exploded perspective view of the cell units U6 and U5. The rod 3A is made of a conductive material such as copper, and the rods 3B and 3C are made of an electrically insulating material such as resin. The rods 3A to 3C are connected by screw fastening. That is, the rod 3B is connected to the lower portion of the rod 3A by screwing the male screw portion 30 formed on the lower end side of the rod 3A and the female screw portion 31 formed on the upper end side of the rod 3B. Furthermore, the rod 3A is connected to the lower portion of the rod 3B by screwing the male screw portion 30 formed on the lower end side of the rod 3B and the female screw portion 31 formed on the upper end side of the rod 3A. The connection between the rod 3C and the rod 3A is the same.
[0014]
A cell voltage detection line 6g is attached between the rod 3A in FIG. 4 and the rod 3B below it. A cell voltage detection line 6e is attached between the rod 3B and the lower rod 3A. In addition, the cell voltage detection line 6f is attached between the rod 3C and the rod 3A. Each rod 3A is inserted through a through hole 20 formed in the bus bars 2A and 2B. As a result, the lateral displacement of the bus bars 2A and 2B, that is, the cell units U1 to U6, is prevented.
[0015]
As shown in FIG. 1, the rods 3 </ b> A and 3 </ b> C at the lowermost end are fixed to the panel 4 </ b> B using male screws 30. On the other hand, the panel 4A is fixed to the rods 3A and 3C at the uppermost end by bolts 5. When the rods 3A to 3C are connected, the bus bars 2A and 2B of the cell units U1 to U6 are fixed to the rod 3A by welding or the like as shown in FIG. Thereby, bus bar 2A and bus bar 2B are electrically connected via rod 3A, and bus bars 2A and 2B and rod 3A are set to the same potential.
[0016]
As a result, the negative electrode side bus bar 2B of the cell unit U1 is connected to the positive electrode side bus bar 2A of the cell unit U2 disposed on the upper side, and the negative electrode side bus bar 2B of the cell unit U2 is connected to the positive electrode of the cell unit U3 disposed on the upper side thereof. It is connected to the side bus bar 2A. That is, the cell units U1 to U3 are connected in series. The cell units U4 to U5 are similarly connected in series. The bus bar 2A of the cell unit U1 and the bus bar 2B of the cell unit U2 are electrically insulated by the rod 3B.
[0017]
As described above, in this embodiment, the bus bars 2A and 2B are provided in the extending direction of the tabs 1b and 1c of the cell 1, and the tabs 1b and 1c are connected to the bus bars 2A and 2B without being bent. And bus-bar 2A, 2B set to the same electric potential in the case of series connection is made to connect with the electroconductive rod 3A. For example, in the case of a general connection method in which the tabs 1b and 1c are connected using the common bus bar 200 as shown in FIG. 5, the tabs 1b and 1c cannot be avoided from being bent. In this embodiment, such bending of the tabs 1b and 1c can be prevented. As a result, it is possible to ensure the strength of the tabs 1b and 1c and improve the durability and reliability. Furthermore, since part of the rods 3A to 3C (rod 3A) provided to prevent displacement of the cell units U1 to U6 is also used for electrical connection between the bus bars, the number of parts and cost Can be suppressed. Further, by sandwiching the cell voltage detection lines 6a to 6g between the rods 3A and 3B when connecting the rods, the detection lines 6a to 6g can be easily connected to the bus bars 2A and 2B, and a reliable connection can be made. .
[0018]
[Modification]
FIG. 7 is a view showing a modified example of the connection structure between the bus bars 2A and 2B and the rods 3A and 3B. The connection structure between the rod 3A and the rod 3B is the same as that described above. Only the male screw portion 30 of the rod 3B passes through the mounting portion of the bus bar 3A and the cell voltage detection line 6a, and the bus bar 3A and the cell voltage detection line 6a (for example, the crimp terminal to which the cell voltage detection line 6a is attached) The rod 3A and the rod 3B are connected so that the In this case, it is not necessary to weld the bus bars 2A and 2B to the rod 3A, and assembly is facilitated.
[0019]
In the embodiment described above, two parallel-connected ones are connected in series in six stages, but the number of parallel connections and the number of series connections are not limited to the embodiment. The present invention can also be applied to a case where a plurality of cells are connected in parallel vertically. Note that the present invention is not limited to the above-described embodiment as long as the above-described characteristic functions and effects can be obtained.
[0020]
In the correspondence between the embodiment described above and the elements of the claims, the positive electrode tab 1b is a positive electrode terminal, the negative electrode tab 1c is a negative electrode terminal, the rod 3A is a conductive columnar member, and the rods 3B and 3C are electrical. Each of the insulating columnar members is configured.
[Brief description of the drawings]
FIG. 1 is a front view of a cell module M. FIG.
FIG. 2 is a cross-sectional view taken along the line AA of FIG.
FIG. 3 is a view taken in the direction of arrow B in FIG. 1;
FIG. 4 is an exploded perspective view of a portion of cell units U6 and U5.
FIG. 5 is a diagram showing a general connection method for connecting tabs 1b and 1c using a common bus bar 200;
6 is a cross-sectional view illustrating the internal structure of cell 1. FIG.
FIG. 7 is a diagram showing a modified example.
[Explanation of symbols]
1 cell 1a cell main body 1b positive electrode tab 1c negative electrode tab 2A, 2B bus bar 3A, 3B, 3C rod 4A, 4B panel 5 bolt 6a-6f cell voltage detection line M cell module U1-U6 cell unit

Claims (5)

A plurality of tab-type cells each having a sheet-like positive electrode terminal and a negative electrode terminal extending in opposite directions from the outer peripheral edge of the cell body are arranged in parallel, and are arranged in the terminal extension direction, and are identical among the terminals. A cell module in which a plurality of cell units in which pole terminals are connected by a pair of substantially plate-like bus bars are arranged so that bus bars having different polarities face each other,
A through-hole formed in the bus bar of each cell unit and penetrating in the stacking direction of the cell units;
A positioning member that passes through the through holes of the plurality of bus bars arranged in the stacking direction and positions the bus bar at a predetermined position with respect to a direction orthogonal to the stacking direction ;
The positioning member electrically insulates electrically conductive columnar members that electrically connect bus bars set at the same potential adjacent in the stacking direction and bus bars set at different potentials adjacent in the stacking direction. Formed by alternately connecting the columnar members in the stacking direction,
The cell module, wherein the plurality of cell units are connected in series by the conductive columnar member . The cell module according to claim 1,
The cell module, wherein the positioning member is a rod in which the conductive columnar member and the insulating columnar member are alternately connected in the stacking direction . The cell module according to claim 2, wherein
Cell module, characterized by that connecting the electrically insulative columnar member and the conductive columnar member so as to hold a voltage detection line of the two tabs type cell. The cell module according to any one of claims 1 to 3,
A cell module, wherein the bus bar is sandwiched between the conductive columnar member and the insulating columnar member. The cell module according to any one of claims 1 to 4,
The cell module, wherein the conductive columnar member and the insulating columnar member are screwed to each other.

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